Problem: Rewrite ${\dfrac{4^{-9}}{4^{-3}}}$ in the form ${4^n}$.
Explanation: ${ \dfrac{4^{-9}}{4^{-3}} = 4^{-9-(-3)}} $ ${ \hphantom{\dfrac{4^{-9}}{4^{-3}}} = 4^{-6}} $